The title is currently held by Zophkaga Shastamannos. He was a kindly, unimportant sorcerer from the South until the Marju Invasion. After the death of the Zophkaga, he was chosen as the next for reasons that are unclear to anyone. He did do a very good job of handling the Marju threat, though, promoting such figures as Kal'Ceska and Kal'Lamarr, the Great Generals of the West and East respectively. The military reforms they brought about allowed Karthack to repulse the steppeland hordes in the decisive Battle of Kar-Magod.
As a ruler he has distinguished himself by being frugal, leaving the provinces to their own business, delegating authority to competent bureaucrats, and fighting corruption in the central government. He's also, purportedly, a very good husband, and responsible for the excellent harvests his people have enjoyed throughout his reign.